Thread: microwave ovens on 12V

I have a top of the range inverter and 2 x 105Ah Full River batteries and while this setup is overkill for everything else I do, running even a small microwave properly is a bridge too far for it realistically.

The inverter runs the microwave fine, but a 3 to 4 minute run of the microwave drags the batteries down so much I don't bother any more,and pulled the microwave out as I can utilise the space and weight better.

I found that when I'm camping, I really didnt need it, it was just something else to lug around. The 40 year old gas oven in the van is a ripper and does everything we need now.

Thanks everyone. My original suspicions appear to be confirmed. We had taken the house microwave on the few outings the current van has seen but didn't use it or the gas oven. I suspect that a gas oven would be necessary for extended touring but so would a larger van where kitchen space is not so limited.

We're soon to look at a used van that has a microwave but no oven. My wife has previously wanted an oven so I'm looking at options. The van is narrow, fibreglass composite, semi off-road with tandem independent coils and almost new with significant useful extras. I've also been offered a good deal on an already built new one but still no oven.

Thanks Terry - I'll look into your Ecopot suggestion.

Hi Graeme, if you are keen on having a microwave then there is a way to achieve it.

As has been pointed out above, they need very high currents available, to be able to use one.

If you were to use lead acid batteries, you would need at least 200Ah but 300 to 400Ah would be better to get a decent life span from the batteries.

Alternatively, you could go with a lithium battery, and I mean ?ONE? lithium battery.

To run a 1,600w ( 800w cooking power ) microwave for 15 minutes is going to need a tad under 40Ah of battery capacity. So a single 60Ah lithium battery is all you need.

For those doing the math, using lead acid batteries, you need to base your calculations around a 12.0v battery supply voltage.

With a lithium battery, the base voltage is 12.8v.

Graeme, if you think you need to cater for a 20 to 25 minute cook time, then a single 100Ah lithium will easily do the job.

You can use the reverse calculations to work out the drive and/or solar recharge times needed.

200w of solar will recharge the battery on a daily basis, while a drive time of around an hour to an hour and a half will do the same. NOTE, this is just to replace the energy you used while cooking with your microwave.

Anyway, this is just something to consider, if you are planning to keep the "new" van for some time, and plan to use it regularly.

I had forgotten about the performance characteristics of Lithium batteries. I'm reminded when the battery in my drill goes flat which it did a few days ago as it works seemingly at full power then very quickly expires, but then recharges in only a short time.

I note that Lithium batteries are offered as alternatives in some of the quite expensive off-road vans which I thought was just to reduce weight but there are other benefits too.

In my van had a cheap inverter. Oven would run but not cook food. Had to go to a pure sine wave

Sent from my GT-I9507 using AULRO mobile app

Originally Posted by dan007

In my van had a cheap inverter. Oven would run but not cook food. Had to go to a pure sine wave

That comment might have saved some disappointment - thanks!

How about putting the inverter in the car. Run the engine when using the microwave, and the alternator will provide most of the power needed, reducing the load on the batteries.

Aaron